Currently available light reflection sensors are not capable of measuring the light reflection from a relatively large spot size on the top surface of solar panels installed in the field and comparing the results before and after application of a performance enhancement coating. The very small spot size analyzed by a typical sensor using a fiber optic probe is insufficient to accurately measure in one reading an area large enough to determine the average performance across the whole solar panel of solution deposited performance enhancing coatings. This is due in part because variations in the top surface structure of solar panel cover glass and variations in solution deposited coating may not be adequately represented within the very small spot size read by the fiber optic probe. Multiple readings by such a probe would have to be done to develop a statistically significant number of samples to estimate average coating performance. Furthermore, typical fiber optic probe sensors require the use of a separate computing device, such as a laptop computer, to run the calculations required to produce human readable data. The process of taking numerous measurements and transporting and setting up a typical fiber optic sensor with a separate computing device for each solar panel to be measured is relatively cumbersome and time consuming compared with a device with integrated computing and human readable display that can determine the average performance difference in light reflection properties by taking just one measurement before and just one measurement after application of a performance enhancement coating.